Ventilating system



1935. A. RICHTER VENTILA'I'ING YSTElL Filed May 19, 1931 $120622; zl fawn y UNITED STATES PATENT OFFICE- Ap l cation May 19, 1

In Germany The invention relates to an arrangement for ventilating rooms by heat and moisture exchange considerably from the tempratiire of the outer atmosphere. It is immaterial whether the chambers are at a-higher temperature than the outer atmosphere or at a lower temperature. According to the invention two heat exchangers of thin sheet metal through which the air passes alternately in opposite directions are built into apertures which connect the chamber with the outer atmosphere. With this arrangement it is possible to preheat the cold fresh air and to bring it to the correct humidity and thus avoid the undesirable sensation of draughts. In particular it is possible to bring the fresh air to the same condition in respect of temperature and humidity as the air already within the chamber, prior to its introduction into the chamber. For this purpose it has already been proposed to provide separate heating or cooling devices for the freshly introduced air but for the most part the control has been effected by an indirect heating of the air and a subsequent satm'ation with water vapour. In this way the appliances are rendered complicated and bulky. At the same time a considerable resistance to the flow of the air has to be overcome.

The present invention departs from the methods hitherto employed in that a direct cooling or preheating is effected, it being rendered possible at the same time to control the moisture content of the air to the desired extent. In order to attain this the air discharged from the chamber and the fresh air are passed in opposite directions through devices in which the discharged air and the fresh air are brought alternately for short periods into contact with the same surfaces or walls. In this way, for example, the warm current of air yields a considerable portion of its heat and moisturecontent to these surfaces. The heat and the moisture is stored in'the material of the device for a short time and in the subsequent period the stored heat and moisture is transferred to the cold air current. Heat is stored in that the temperature of the material is raised. The moisture is stored in that the water vapour which separates out in the form of a precipitate after attaining dew point in the cooling of the warm= air current is deposited in the form of a precipitate on the surfaces of the device. After interchanging the paths of flow of the cold and the warm air currents, the cold air current passes over these surfaces of the device and is warmed 931, Serial No. 538,564 May 28, 1930 thereby. This warm air current takes up the precipitated moisture to an extent corresponding to its saturation capacity. In this way a detrimental accumulation of precipitate water is also avoided. These advantages are attained particularly in that the air discharged from the chamber and the fresh air are passed alternately for short periods over the same surfaces or walls of a heat storing device of corresponding construction.

An embodiment is shown diagrammatically by way of example in the drawing:

In the wall of the chamber two heat exchange devices l3 and I3 are provided which cooperate with a fan 2|. In order to permit of altering the direction of flow in this case two flaps 22, 22' are provided which alternately connect one or the other heat exchange devices with the passage or conduit 23. The fan may be used either for drawing air out of the chamber and forcing 'it through the heat exchange devices or if desired it can be used to draw air through the heat exchange devices and inject it into the chamber. By appropriately positioning the flaps 22, 22' the heat exchange devices can be connected alternately and at short intervals with the passage 23. The mode of operation of the apparatus will now be explained:

It is assumed that the chamber to be ventilated is a refrigerator at a temperature of 2 C. and that the outer or atmospheric air is at a temperature of +22 C. The heat exchange devices l3 and I3 will be at the temperature of the refrigerator i. e., at about -2 C. in the zone adjacent the refrigerator and in the zone remote from the refrigerator will have the temperature of the outer. atmosphere i. e., +22 C. The intermediate zones will be at intermediate temperatures. The side of the heat exchange device adjacent the refrigerator will be termed the cold side and the side exposed to the atmosphere will be termed the warm side. On its path through the heat exchange device the fresh air which is introduced will cool as it progresses from the warm to the cold side, giving up a part of its heat content to the surfaces of the heat exchange device; after attaining dew point excess moisture is deposited as' precipitate on the surfaces of the heat exchange device. In the subsequent period the air flowing out from the refrigerator will be warmed by the surfaces of the heat exchange device as it flows from the cold to the warm side and takes up heat from the surface of the heat exchange device,.at the same time taking up the moisture precipitated by virtue of its saturation capacity.

the chamber (refrigerator).

Thus the freshly introduced air is cooled and dried in that its heat and moisture are transferred to the cold waste air.

In the operation described the fresh air had a higher initial temperature than the air in The method can, of course, be carried out with the same arrangement if the fresh air has a lower initial temperature than the air within the chamber (e. g. ventilation of living rooms in cold winter weather). The same operations then occur but in the opposite sense. In each case the fresh air passes into the chamber to be ventilated at approximately the same temperature as exists in the chamber in that it is heated or cooled by the waste air according to the individual conditions.

I claim:

1.' Apparatus for ventilating rooms by heat and moisture exchange, comprising at least two heat exchangers of thin sheet metal, a conduit having a fan cooperating therewith and communicating with said exchangers, and a flap for each exchanger and provided in the conduit for periodically and alternately connecting the conduit in communication with one of the heat exchangers and the fan by periodically reversing both flaps.

2. Regenerative heating system for rooms comprising two heat exchangers of large metallic surface area arranged in a wall of the room to be heated with their outer ends open, a channel open at both ends arranged inside the room with the inner ends of the exchange devices in communication with the channel, a fan in an opening of the channel between its ends, and flap valves in said channel before each exchange device, one flap valve connecting the associated exchange device with an end of the channel and the other flap valve connecting the other exchange device with the fan, said flap valves being movable to alternate the connections of the exchange devices with the fan,and the ends of the channel to produce a regenerative flow through the 20 system.

ALFRED RICHTER. 

